Asphaltic coating composition and material coated therewith



Patented Mar. 26, 1935 UNITED STATES PATENT OFFICE ASPHALTIC COATING COMPOSITION AND MATERIAL COATED TH'EBEWITH Harold James Barrett, Wilmington, DeL, assignor to E. I. du Pont de Nemours & Company, Wilmington, DeL, a corporation of Delaware No Drawing.

Application January 31, 1931, Serial No. 512,738

15 Claims. (Cl. 1334-26) This invention relates to an improved asphalt varnish and to products coated therewith. More particularly the inventiori relates to artificial leather comprising fabrics or other flexible sheet material provided with a top coat of the improved asphalt varnish.

Asphalt varnishes, as disclosed in Patent 1,795,199, have been found to be especially valuable as a final coat for materials, such as automobile top materials, which are exposed to the sun and weather. These varnishes have been improved in certain respects by the incorporation of synthetic resins of'the oil modified polyhydric alcohol-polybasic acid type, as disclosed in the application of Andrew J. Hemmer, Serial No. 478,549, filed August 28, 1930. I have discovered that these varnishes comprising asphalt and polyhydric alcohol-polybasic acid resins may be 1 further improved, as will more fully appear in the following specification. I This invention has as an object the production of improved asphalt varnishes.

A further object resides in the production of an improved artificial leather or coated fabric, which is especially adapted for use as an automobile top material. Other objects will appear hereinafter. 1

I have discovered that coatings produced by asphalt varnishes containing polyhydric alcoholpolybasic acid resins are improved with respect to compatibility of the resin with the asphalt,

' the durability. of the coating, and the capability of the coating to retain a high luster for a long period of time, if the component of the resin comprising the reaction product of the polybasic acid with the polyhydric alcohol is kept low, (below 23%), as compared with the resins of the Hemmer application which discloses resins containing higher percentages (23.3% to 40% of polybasic acid glyceride). Whereas these limits are-expressed in terms of "polybasic acid" glycerides, they are equally applicable to polybasic acid derivatives of other polyhydric alcohols such as, for example, glycol or pentaerythritol. However, since phthalic acid ('or anhydride) is my preferred polybasic acid and glycerol is my preferred polyhydric alcohol, the polybasic acidpolyhydric alcohol constituent of my resin compositions is referred to throughout my specification as phthalic glyceride content.

I have further discovered that the improvements referred to are much more marked when rosin or other natural acidic resins such as kauri 0r,Run Congo, are incorporated into 011' modified polyhydric alcohol-polybasic acid resins during the process of their manufacture by substituting the natural resins for a part of the drying or semi-drying oil or corresponding oil acids; ,1 have also found that results comparable to the introduction of the natural acidic resins may be obtained with naphthenic acids. It is to be noted, however, that when the natural acidic resins or naphthenic acids are used as 'above mentioned, it is not necessary for the attainment of the objects of the invention to keep the phthalic glyceride content of the resin as low as when the natural acidic resins or naphthenic acids are absent. It is apparent, of course, that the resin, Congo, naphthenic acids, etc., can be previously esteriiied and added to the reaction mixture in the'form of the ester, such as for example rosin glyceride, commonly known as ester The following examples are illustrative of the methods used in carrying out the invention.

Example 1 Parts by weight Petroleum asphalt 100 Solvent naphtha .s 100.49

Resin A (acid No. 15.4) 20.00

Turpentine 20.00

Cobalt drier 0.17

The asphalt is heated to 500 F., allowed to cool to 425 R, an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt'is completely dissolved. To this solution is added 40 parts by weight of a 50% solution of resin A in turpentine and 0.65 parts by weight of a cobalt drier solution containing 1.45% cobalt.

Resin A, used in the above composition, was formed from-the following ingredients, using the proportions indicated:

' The asphalt is heated to 500 F., allowed to cool to 425 F.,*.an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt is completely dissolved. To this solution is added 320 parts by weight of a 50% solution of proportions indicated:

-Glycerol 11.84 Succinic acid 7.66 Linseed oil acids 66.98 Rosin 13.52

Example 5 Parts by weight Petroleum asphalt. 100.00 Solvent naphtha 102.02 Resin D (acid NO. 63.80) 80.00 Turpentine; 80.00 Cobalt drier 0.68

resin A in turpentine and 16.4 parts by weight of a drier solution containing 1.47% lead and 0.41% manganese.

Example 3 Parts by weight Gilsonite 100.00 Solvent naphtha 112.28 ResinB (acid No. 49.2) 160.00 Turpentine 160.00 Lead-manganese drier 4.12

The gilsonite is heated to 500 F., allowed to cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the gilsonite is completely dissolved. To this solution is added 320 parts by weight of a 50% solution of resin B in turpentine and 16.4 parts by-weight of a drier solution containing 1.47% lead and 0.41% manganese.

Resin B, used in the above composition, was formed from the following ingredients, using the 7 Parts by weight Glycerol 11.23 Adipic acid 7.96 Linseed oil acids 67.25 v Rosin 13.56

Example 4 Parts by weight Petroleum asphalt 100.00 Solvent naphtha 103.07 =Resin C (acid No. 64.39) 40.00 Turpentine 40.00 Lead-manganese drier 1.03

The asphalt is heated to-500 F., allowed to cool to 425 F., an equal weight of solvent naphtha. is added, and the mixture is stirred until the asphalt is completely dissolved. To this solution is added parts by weight of a 50% solution of resin C in turpentine and 4.1 parts by weight of a drier solution, containing 1.47% lead and 0.41% manganese;

Resin C, used in the above composition, was formed from the following ingredients, using the proportions indicated:

1 Parts by weight The asphalt is heated to 500 F., allowed to cool to425 F., an equal weight of solvent naphtha is added, and-the mixture is stirred until the asphalt is completely dissolved. To this solution is added parts by weight of a 50% solution of resin D in turpentine and 2.7 parts by weig t 01 a.

cobalt drier solution containing 1.45% cob is.

Resin D, used in the above composition, was formed from the following ingredients, using the proportions indicated:

The asphalt is heated to 500 F., allowed to cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt iscompletely dissolved. To this solution is added 80 parts by weight of a 50% solution of resin E in turpentine and 0.65 parts by weight of a cobalt drier solution containing 1.45% cobalt.

Resin E, used in the abbve composition, was formed from the following ingredients, usingthe The asphalt is heated to 500 F., allowed to cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt is completely dissolved. To this so-. lution is added 96 parts by weight of a 50% solution of resin F in turpentine and 4.92 parts vby weight of a drier solution containing 1.47% lead and 0.41% manganese.

Resin F. used in the above composition, was formed from the following ingredients, using the proportions indicated:

Parts by weight Glycerol 11.00 Phthalic anhydride -1--. 7.30 Linseed oil acids .4. 67.97 Naphthenic acids 13.73.

. 100.0 Example 8 I Parts by weight Petroleum asphalt 100.00 Solvent naphtha -1. 103.07 Resin G (acid'No. 14.48) 40.00 Turpentine 40.00 Lead-manganese drier 1.03

Parts by weight Glycol 10.95 Phthalic anhydride 7.29 Linseed oil acids 68.04 Rosin 13.72

Example 6 Parts by weight Petroleum asphalt 100.00 Solvent naphtha 100.48 Resin E (acid No. 13.53) 40.00 Turpentine 40.00 Cobalt drier 0.17

1,905,957 The asphalt is heated to 500 F., .allowed to" cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt is completely dissolved; To thisgsolution is added 80 parts by weight of a 50% so-' lution of resin G is turpentine and 4.1 parts by weight of a drier solution containing 1.47% lead and 0.41% manganese. I

Resin G, used in the above composition, was formed from the following ingredients, using the proportions indicated:

Parts byweight Glycerol 10.60 Phthalic anhydride 7.31 Linseed oil acids 68.14 Run C0ngo. 13.95

Example 9 Parts by weight Petroleum asphalt 100.00 Solvent naphtha 102.02- Resin H (acid No. 22.1) 80.00 Turpentine 80.00 Cobalt drier 0.68

The asphalt is heated to 500 F., allowed to cool to 425 R, an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt is completely dissolved. To this solution is added 160 parts by weight 01' a 50% solution of resin H in turpentine and 2.7 parts by weight of a cobalt drier solution containing 1.45% cobalt.

Resin H, used in the above composition, was formed from the following ingredients, used the proportions indicated:

' Glycerol e 12.91 Phthalic anhydride -f .L.... 13.82 Linseed oil acids 55.98 Rosin 17.29

Example 10 Parts by weight Gilsonite 100.00 'Sol'vent naphtha 106.15. Resin I (acid No. 23.6) 80.00 Turpentine 80.00 Lead-manganese drier 2.05

The gilsonite is heated to 500 F., allowed'to cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the gilsonite is completely dissolved. To this solution is added 160 parts by weight of a 50% solution of resin I in turpentine and 8.2 parts' by weight of a drier solution containing 1.47% leadand 0.41% manganese. I

Resin 1, used in the above composition, was formed from the following ingredients, using the proportions indicated:

Parts by weight Glycerol 11.06 Phthalic anhydride 7.30 Linseed oil acids g 54.35 China wood oil acids 13.59

Rosin 13.70

Parts by weight Example 11 Parts by weight. Petroleum asphalt 100.00 Solvent naphtha 103.07 Resin J (acid No. 21) 40.00 Turpentine 40.00 Lead-manganese drier 1.03

The asphalt is heated to 500 F., allowed to cool to 425 R, an equal weight of solvent naph-v tha is added, and the mixture is stirred until the asphalt is completely dissolved. To this solution is added 80 parts by weight of a 50% solution of resin J inturpentine and 4.1 parts by weight of a drier solution containing 1.47% lead and 0.41% manganese.

- Resin J, used in the above co'm'positiomwas formed from the following ingredients, using the proportions indicated: I Parts by weight Glycerol 6.66 Phthalic anhydride 7.49 China wood oil acids 23.29 Deodorized sardine oil 48.47 Rosin 14.09

Example 12 Parts byweight Gii's'onite 100.00 'Solvent naphtha 112.28 Resin K (acid No. 27.2) 160.00 Turpentine 160.00 Lead-manganese drier 4.12

The gilsonite is heated to 500 F., allowed to cool to 425 F., an equal weight of solventnaph- 'tha is added, and the mixture isstirred until the gilsonlte is completely'dissolved. To this solution is added 320 parts by weight of a 50% solution of resin K in turpentine and 16.4 parts by weight of a drier solutioncontaining- 1.47% lead and 0.41% manganese.

Resin K, used in the above composition, was

formed from the following ingredi t using th proportions indicated:

The asphalt is heated to 500 F., allowed to cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt is completely dissolved. To thissolution is added 120 parts by weight of a 50% solution of resin A in turpentine. I

proportions indicated,

Example 14 Parts by weight Petroleum asphalt 100.00 Solvent naphtha 100.00 Resin L (acid No. 24.2) -1... 40.00 Turpentine 40.00

The asphalt is heated to 500 F., allowed to cool to 425 F., an equal weight of solvent naphtha is added, and the mixture is stirred until the asphalt is completely dissolved. To this solution is added 80 parts by weight of a 50% solution of a resin Lin turpentine.

Resin L, used in the above composition, was formed from the following ingredients, using the proportions indicated:

The gilsonite is heated to 500 F., allowed to cool to 425 R, an equal weight of solvent naphtha is added, and the mixture is stirred until the gilsonite is completely dissolved. To this solution is added 160 parts by weight of a 50% solution of resin M in turpentine.

Resin M, used in the above composition, was formed from the following ingredients, using the Parts by weight Glycerol 10.17

Phthalic anhydride 3.65

. Linseed oil acids 81.61

Rosin j 4.57

When low phthalic glyceride content of the resin is solely relied upon to produce my improved asphalt varnish, the phthalic glyceride content of the resin may range between about 5% and about 23% by weight of the resin, the remainder of the resin consisting essentially of drying oil acid glycerides. Expressed in terms of its reacting ingredients, the resin may be comprised of the reaction product of from about 1.5% to 14.6% glycerol, 3.5% to 17% phthalic anhydride, the remainder being oil or oil acid of the drying or' semi-drying class containing oil acid amounting to from 86% to 69% of the reacting ingredients. In the case oi! these low phthalic glyceride containing resins, it is preferred to use resins containing about phthalic glyceride and 90% drying oil acid glyc-.

erides, these figures corresponding to about 11.31% glycerol, 7.28% phth'alic anhydride, and 81.41% drying oil acids.

The incorporation-of rosin into the polyhydric alcohol-polybasic acid resin is, as previously noted, an important aid in eiiecting compatibility between the asphalt and resin and in conferring improved durability of the film yielded by the asphalt varnish. varnishes that have proved to be mostdurable have been prepared from resins containing approximately 10% phthalic glyceride, rosin glyceride, and 75% drying oil acid glyceride. These percentages may, however, be varied somewhat, as it is possible to produce excellent asphalt varnishes with resins in which the phthalic glyceride content ranges from 5% to 40% and in which the rosin glyceride varies from 5% to 25%, the drying oil glyceride constituting, in each case, the bulk of the remainder of the resin content. It is to be noted that the total of the phthalic glyceride and rosin glyceride can rise too high, with the result that the resin is so short in oil (deficient in drying oil acid glycerides) that it is no longer satisfactorily compatible with'the asphalt. The resin should not, therefore, fall below about 45% drying or semi-drying oil acid glycerides, which corresponds to about 40% drying orsemi-drying oil acids. It is to be understood that the glyoerides mentioned in this specification refer, not to phthalic glyceride, rosin glyceride, and drying oil acid glycerides, separately,

but to synthetic mixed phthalic-rosin-drying oil acid glycerides in which some of the. hydroxyl groups of each glycerol molecule have probably been esterified by phthalic anhydride, some by rosin, and some by drying or semi-drying oil acids. Glyceride compositions of my resins are calculated from the batch compositions, that is, from the weights of ingredients charged to the kettle before formation of the resin. Thus, the glyceride compositions do not take cognizance of small amounts of ingredients which may be volatilized during preparation 01' the resins. This discrepancy, however, is quite small and is entirely overbalanced by the.convenience of being able to reason in terms of solid and softening glyceride ingredient ratios in the resin. The pre-.

ferred percentages of the rosin-containing resin referred to above, but expressed in terms of the reacting ingredients which produce the resinous reaction product, termed herein as a polyhydric alcohol-polybasic acid resin, are approximately asfollows: 11% glycerol, 7.3% phthalic anhydride, 13.7% rosin, and 68% drying or semi-drying oil acids or the equivalent amount of oil. Of course, if 011 is used instead of oil acids in this formula less glycerol should be used. In this case only about 4% of glycerol is necessary if drying oil is used.

The limits oi these compositions, expressed in terms of their reacting ingredients, within which improved asphalt varnishes may be made are about as follows: glycerol from about 1.5%-to 17.5%, phthalic anhydride from'3.5% to 29%, rosin from 4.5% to 23%, the remainder of the resin in each instance being comprised of drying or semi-drying oil acids or the corresponding drying or semi-drying oils together with small amounts of other modifying ingredients.

The improvement incompatibility with asphalt of polyhydric alcohol-polybasic acid resins in' which low phthalic glyceride content alone is relied upon to produce the increased compatibility, as well as the further increase in compatibility resul ing from the presence of rosin glyceride 1,995,957 in the resin, is evidenced by the acceptable gallon lengths of the resin that may be used with the asphalt. A gallon oil length, as used in the varnish trade, designates a gallon of oil per 100 pounds of gum. By weight, this ls generally about eight pounds of oil to 100 pounds of gum.

The term gallon or fgallon lengt as-used herein, designates eight pounds of oil modified polyhydricalcohol-polybasic acid resin per 100 pounds of asphalt. The term acceptable gallon" lengt lens of resin that are compatible with, and will refers to the-maximum number of galproduce a homogeneous mixture with 100 pounds of asphalt. Considering the acceptable gallon lengths which may be realized with resins of low phthalic glyceride content containing no rosin or and phthalic glyceride content will, with the aid of these blending agents, yield compatible varnishes of 75, 40, and 40 gallons, respectively, whereas without the use of blending agents the acceptable gallonlengths are 40, 25 and 25 gallons, respectively.

As the phthalic glyceride content rises above about 23%, the acceptable gallon lengths and the durability of the asphalt-modified polyhydric alcohol-polybasic acid resin systems diminish. Thus, resins containing 23.3% phthalic glyceride and 76.7% linseed oil acid glycerides, and resins containing 37.62% phthalic glyceride and 62.38% linseed oil glycerides, yield acceptable gallon lengths not greater than 20, with or without the use of a blending agent. Furthermore, these gallon lengths or resins having high phthalicglyceride content are possible only when the resin has a relatively. high acid number. With lower acid numbers, the compatibility of the resins with asphalt is still further decreased.

The incorporation of rosin into the oil modified polyhydrlc alcohol-polybasic acid resin effects a still further increase in compatibility between the resin and asphalt. A resin containing 5% phthalic glyceride, 5% rosin-glyceride, and 90% linseed oil acid glycerides having an acid number of 25 will yield a 40 gallon varnish without a blending agent and a 100 gallon varnish with a lead-manganese resinate blending agent, whereas corresponding resins which do not contain rosin glyceride are not compatible with asphalt.

above 25 gallons without. a blending agent and above 40 gallons with a lead-manganese resinate blending agent. of rosin glyceride for a part of the phthalic glyceride in the resin may further be observed from The effect of the substitution glyceride and 62.38% linseed oil acid glycerides. The resin of the preferred rosin glyceride content, i. e., 15% rosin glyceride, 10% phthalic glyceride, and 75% linseed oil acid glycerides, yields a 35 gallon varnish withouta blending agent and a'40 gallon varnish with a blending agent, as compared to gallon lengths produced by the previously mentioned resin containing 1 23.3% phthalic glyceride and 76.7% linseed oil acid glycerides'. The preferred resin containing rosin glyceride is somewhat more compatible with the asphalt than the preferred low phthalic.

glyceride resin, (10% phthalic glyceride and 90% linseed oil acid glycerides) containing no rosin, as will be noted from the fact that the latter resin yields varnishes of gallon length without a blending agent as compared with the gallon varnishes produced from the preferred resin 'containing rosin glyceride. In general, the statement may be made that the higher the phthalic glyceride content, the more rosin will be necessary in order to enact improved compatibility with the asphalt. In most cases systems C0111- taining rosin modified resins'of relatively high phthalic glyceride content pass thru a minimum point of compatibility, which makes it diiiicult to define acceptable gallon lengths. Thus, a resin containing 40% phthalic glyceride, 15%

rosin, and linseedoil acid glycerides, acid number 25.5, yields an acceptable 30 gallon asphalt varnish, but the 10 gallon varnishes are concerned, as will be apparent from the increased gallon lengths capable of being produced, aremarkedly more compatible with asphalt than are the polyhydric alcohol-polybasic acid resins previously used in making asphalt varnishes. The

higher gallon length varnishes, however, some times exhibit undesirable characteristics such as 1 poor durability, tackiness, dullness, and the development-of a blue color in the film. It is to be understood, therefore, that the present invention resides, not in the production of asphalt varnishes of exceptional gallon length of resin, but in my discovery that the resins of low phthalic glyceride content and the rosin modified resins herein described produce asphalt varnishes of improved durability up to 20 gallons in resin length. I have found that in asphalt varnishes of not more than 20 gallons resin length the durability and compatibility with asphalt go hand in hand, and, as previously pointed out, the resins included in the present invention are characterized by exceptional compatibility with asphalt.

The durability of th'e films yielded by the varnish, as well as the'acceptable gallon lengths possible, will vary somewhat for asphalts from different sources. I prefer to use a petroleum residue asphalt which has been steam refined, as distinguished from petroleum residue asphalt which has been refined by other methods, as for instance, by blowing with air. I have found that the most durable varnishes are produced from steam refined petroleum residue asphalt. The

T. M. standards, 1921, page 944, under the serial designation'D-36-21. It is desirable, furthermore, that the steam, refined petroleum residue sheet material" covers the fabrics such as paper or cloth coated with a layer of material such as rubber or pyroxylin by spraying, spreading, calendering, or by other known methods of application. Pigments, such as carbon black and asbestine may be added to the varnishes herein disclosed 1. A coating composition comprising asphalt,

an organic solvent, and a polyhydric alcoholpolybasic acid resin the composition of which may be calculated as from up to 23% polybasic acid ester, the remainder being fatty oil acid ester, said resinv comprising the reaction product of a polyhydric alcohol, a polybasic acid and a modifying agent selected from the class consisting' of fatty oils and fatty oil acids, the proportion of said resin to asphalt. present in the composition being substantially, less than the maximum proportion of said resin to asphalt which is capable of forming a homogeneous blend.

2. The composition set forth in claim 1 in which the polyhydric alcohol is glycerol, the polybasic acid is phthalic anhydride, and the fatty oil acids are linseed oil acids.

3. A coating composition comprising asphalt, an organic solvent and a glyceryl phthalate resin the composition of which may be calculated as about glyceryl triphthalate and about 90% oil fatty acid glycerides, said resin comprising the reaction product of glycerol, phthalic anhydride, and a modifying agent selected from the class consisting of fatty oils and fatty oil acids, the proportion of said resin to asphalt present in the composition being substantially less than the maximum proportion of said resin to asphalt which is capable of forming a homogeneous blend.

4. A coating composition comprising asphalt, an organic solvent, and a polyhydric alcoholpolybasic acid resin comprising the reaction prod-,

uct of a polyhydric alcohol, a polybasic acid, a modifying agent selected from the class consisting of fatty oil and fatty oil acids, and an additional modifying agent selected from the class consisting of resinic acid and naphthenic acids, the composition of said resin being calculated as from 5% to 40% polybasic acid ester, the remainder being fatty oil acid ester and the ester of said additional modifying agent, the fatty oil acid ester predominating, the proportion of said resin to asphalt present in the composition being substantially less thanT-the maximum proportion of said resin to asphalt which is capable of forming a. homogeneous blend.

5. The composition set forth in claim 4 in which the polyhydric alcohol is glycerol, the polybasic acid is phthalic anhydride, the fatty'oil acids are 7 linseed oil acids, and the resinic acid is rosin.

from 5% to 25% resinic acid ester, and the iremainder being fatty oil acid ester, the proportion of said resin to asphalt present in the 'composition being substantially less than the maximum proportion of said resin to, asphalt which is capable of forming a homogeneous blend.

'1. The composition set forth in claim a in which the polyhydric alcohol is glycerol, the

polybasic acid is phthalic anhydride, the. fatty' oil acids are linseed 'oil acids, and the resinic acid is rosin.

8. A- coating composition comprising an organic solvent," asphalt, and an oil modified p'olyhydric alcohol-polybasic acid resin comprised of the reaction product of a polyhydric alcohol, a polybasic acid, a natural acidic .resin, and a modifying agent selected fromthe class consisting of drying oils, semi-drying oils, drying oil acids, and semi-drying oil acids, said resin being a mixed ester which may be calculated as approximately 10% phthalicgglyc'eride, rosin glyceride, and

75% drying oil acid glyceride, the proportion of said resin to asphalt present in the composition being substantially less than the maximum proportion ofsaid resin to asphalt which is capable.

of forming a homogeneous blend.

9. As an article'of manufacture a flexible fab- I ric sheeting having a final coat of dried varnish comprising asphalt and a polyhydric alcoholpolybasic acid resin the composition of which may be calculated as from 5%, to 23% polybasi acid ester, the remainder being fatty oil acid ester, said'resin comprising the reaction product of a polyhydric alcohol, a polybasic acid and a modifying agent selected from the class consisting of fatty oils and fatty oil acids, the proportion of said resin to asphalt present in the composition being substantially less than the maximum proportion of said resin to asphalt which is capable of forming a homogeneous blend.

10. The article set forth in claim 8 in which the" polyhydric alcohol is glycerol, the polybasic acid is phthalic anhydride, and the fatty oil acids are linseed oil acids.

oil acid ester and resinic acid ester, the fatty oil acid ester predominating, said resin comprising the reaction product of a polyhydric alcohol, a

polybasic acid, a resinic acid, and a modifying agent selected from the class consisting of fatty oilsand fatty oil acids, the proportion of said resin to asphalt present in the composition being substantially less than the maximum proportion of said resin to asphalt which is capable of forming a homogeneous blend. 1

12. The. article set forth in claim 11 in which the polyhydric alcohol is glycerol, the polybasic acid is phthalic anhydride, the fatty oil acids are I linseed oil acids, and the resinic acid is rosin.

13. As an article of manufacture a rubber coated flexible fabric'sheeting having a final coat of mainder being fatty oil acid ester, the proportion of said'resin to asphalt present in the composition being substantially less than the maximum proportion of said resin to asphalt which is capable of forming a homogeneous blend.

14. The coating composition set forth in claim 1 in which the resin and asphalt are present in the composition in the proportion of from to l pounds of resin per pounds of asphalt.

15. The composition set forth in claim 4 in which the resin and asphalt are present in the composition in the proportion of from 20 to pounds of resin per 100 pounds of asphalt.

' HAROLD JAMES BARRETT. 

